AngularJS 使用ngOption实现下拉列表

2022-04-16 09:03:08

下拉列表的简单使用

ng-option指令使用很简单，只需要绑定两个属性：

一个是ng-model用于获取选定的值；

另一个是ng-options用于确定下拉列表的元素数组。

<select ng-model="engineer.currentActivity" class="form-control" ng-options="act for act in activities"></select>

上面这条语句就是把选择的值与engineer.currentActivity进行双向数据绑定，然后列表中的选项是activities中的每一个值。数据如下：

$scope.engineer = {
                name: "Dani",
                currentActivity: "Fixing bugs"
            };
         
            $scope.activities =
            [
                "Writing code",
                "Testing code",
                "Fixing bugs",
                "Dancing"
            ];

运行结果如：

为了美观一点，这里引用了bootstrap。

<html ng-app="myApp">
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
    <script src="http://apps.bdimg.com/libs/angular.js/1.2.16/angular.min.js"></script>
    <link rel="stylesheet" href="http://apps.bdimg.com/libs/bootstrap/3.3.0/css/bootstrap.min.css">  
    <script src="http://apps.bdimg.com/libs/jquery/2.1.1/jquery.min.js"></script>
    <script src="http://apps.bdimg.com/libs/bootstrap/3.3.0/js/bootstrap.min.js"></script>
</head>
<body>
    <div ng-controller="EngineeringController" class="container">
        <div class="col-md-12">
            {{engineer.name}} is currently: {{ engineer.currentActivity}}
        </div>
        <div class="col-md-4">
            <label for="name">Choose a new activity:</label>
            <select ng-model="engineer.currentActivity" class="form-control"
                    ng-options="act for act in activities">               
            </select>
        </div>
    </div>
    <script type="text/javascript">
         var myAppModule = angular.module("myApp",[]);
         myAppModule.controller("EngineeringController",["$scope",function($scope){
            $scope.engineer = {
                name: "Dani",
                currentActivity: "Fixing bugs"
            };
         
            $scope.activities =
            [
                "Writing code",
                "Testing code",
                "Fixing bugs",
                "Dancing"
            ];
         }]);
    </script>
</body>
</html>

复杂对象，自定义列表名称

有的时候下拉列表并不是单纯的字符串数组，可能是json对象，例如：

$scope.activities =
             [
                 { id: 1, type: "Work" , name: "Writing code" },
                 { id: 2, type: "Work" , name: "Testing code" },
                 { id: 3, type: "Work" , name: "Fixing bugs" },
                 { id: 4, type: "Play" , name: "Dancing" }
             ];

这个时候，绑定的数据就必须是与这里面的格式相同的数据，比如直接复制其中一条：

$scope.engineer = {
                 name: "Dani" ,
                 currentActivity: {
                     id: 3,
                     type: "Work" ,
                     name: "Fixing bugs"
                 }
             };

当然也可以直接指定成：

$scope.engineer = {currentActivity:activities[3]}

然后在指令中可以循环列表拼接处下拉框的名称

<select 
        ng-model = "engineer.currentActivity"
        class="form-control"
        ng-options = "a.name +' (' + a.type + ')' for a in activities" >               
</select >

运行效果如：

全部的代码如下：

<html ng-app="myApp">
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
    <script src="http://apps.bdimg.com/libs/angular.js/1.2.16/angular.min.js"></script>
    <link rel="stylesheet" href="http://apps.bdimg.com/libs/bootstrap/3.3.0/css/bootstrap.min.css">  
    <script src="http://apps.bdimg.com/libs/jquery/2.1.1/jquery.min.js"></script>
    <script src="http://apps.bdimg.com/libs/bootstrap/3.3.0/js/bootstrap.min.js"></script>
</head>
<body>
    <div ng-controller="EngineeringController" class="container">
        <div class="col-md-12">
        {{engineer.name}} is currently: {{ engineer.currentActivity}}
        </div>
        <div class="col-md-4">
            <label for="name">Choose a new activity:</label>            
            <select 
            ng-model = "engineer.currentActivity"
            class="form-control"
            ng-options = "a.name +' (' + a.type + ')' for a in activities" >               
            </select > 
        </div>
    </div>
    <script type="text/javascript">
         var myAppModule = angular.module("myApp",[]);
         myAppModule.controller("EngineeringController",["$scope",function($scope){
            $scope.engineer = {
                 name: "Dani" ,
                 currentActivity: {
                     id: 3,
                     type: "Work" ,
                     name: "Fixing bugs"
                 }
             };
         
             $scope.activities =
             [
                 { id: 1, type: "Work" , name: "Writing code" },
                 { id: 2, type: "Work" , name: "Testing code" },
                 { id: 3, type: "Work" , name: "Fixing bugs" },
                 { id: 4, type: "Play" , name: "Dancing" }
             ];
         }]);
    </script>
</body>
</html>

实现下拉列表的分组

其实分组与前面的例子很像，只要把空间中的ng-options的值换成下面：

<select ng-model = "engineer.currentActivity"
        class="form-control"
        ng-options = "a.name group by a.type for a in activities" >               
</select >

添加 group by 就会按照后面的值进行分组

全部代码：

<html ng-app="myApp">
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
    <script src="http://apps.bdimg.com/libs/angular.js/1.2.16/angular.min.js"></script>
    <link rel="stylesheet" href="http://apps.bdimg.com/libs/bootstrap/3.3.0/css/bootstrap.min.css">  
    <script src="http://apps.bdimg.com/libs/jquery/2.1.1/jquery.min.js"></script>
    <script src="http://apps.bdimg.com/libs/bootstrap/3.3.0/js/bootstrap.min.js"></script>
</head>
<body>
    <div ng-controller="EngineeringController" class="container">
        <div class="col-md-12">
        {{engineer.name}} is currently: {{ engineer.currentActivity}}
        </div>
        <div class="col-md-4">
            <label for="name">Choose a new activity:</label>            
            <!-- <select 
            ng-model = "engineer.currentActivity"
            class="form-control"
            ng-options = "a.name +' (' + a.type + ')' for a in activities" >               
            </select >  -->
            <select ng-model = "engineer.currentActivity"
                    class="form-control"
                    ng-options = "a.name group by a.type for a in activities" >               
            </select > 
        </div>
    </div>
    <script type="text/javascript">
         var myAppModule = angular.module("myApp",[]);
         myAppModule.controller("EngineeringController",["$scope",function($scope){
            $scope.engineer = {
                 name: "Dani" ,
                 currentActivity: {
                     id: 3,
                     type: "Work" ,
                     name: "Fixing bugs"
                 }
             };
         
             $scope.activities =
             [
                 { id: 1, type: "Work" , name: "Writing code" },
                 { id: 2, type: "Work" , name: "Testing code" },
                 { id: 3, type: "Work" , name: "Fixing bugs" },
                 { id: 4, type: "Play" , name: "Dancing" }
             ];
         }]);
    </script>
</body>
</html>

按照id进行标识

由于之前的ng-model相当于初始的时候给设定了一个值。当你选择一个下拉列表选项的时候，就会覆盖掉这个初始值。

所以更多的时候会使用一个id进行标识，这样在初始化赋值的时候，只需要设定一个id就可以了。

$scope.engineer = {
                 currentActivityId: 3
             };
         
             $scope.activities =
             [
                 { id: 1, type: "Work" , name: "Writing code" },
                 { id: 2, type: "Work" , name: "Testing code" },
                 { id: 3, type: "Work" , name: "Fixing bugs" },
                 { id: 4, type: "Play" , name: "Dancing" }
             ];

指令可以写成下面的格式

<select 
       ng-model = "engineer.currentActivityId"
       class="form-control"
       ng-options = "a.id as a.name group by a.type for a in activities" >               
</select >

通过 as 前面的值，就可以确定唯一的一个选项

全部代码如下：

<html ng-app="myApp">
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
    <script src="http://apps.bdimg.com/libs/angular.js/1.2.16/angular.min.js"></script>
    <link rel="stylesheet" href="http://apps.bdimg.com/libs/bootstrap/3.3.0/css/bootstrap.min.css">  
    <script src="http://apps.bdimg.com/libs/jquery/2.1.1/jquery.min.js"></script>
    <script src="http://apps.bdimg.com/libs/bootstrap/3.3.0/js/bootstrap.min.js"></script>
</head>
<body>
    <div ng-controller="EngineeringController" class="container">
        <div class="col-md-12">
        current is: {{ engineer.currentActivityId}}
        </div>
        <div class="col-md-4">
            <label for="name">Choose a new activity:</label>            
            <select 
                ng-model = "engineer.currentActivityId"
                class="form-control"
                ng-options = "a.id as a.name group by a.type for a in activities" >               
            </select > 
        </div>
    </div>
    <script type="text/javascript">
         var myAppModule = angular.module("myApp",[]);
         myAppModule.controller("EngineeringController",["$scope",function($scope){
            $scope.engineer = {
                 currentActivityId: 3
             };
         
             $scope.activities =
             [
                 { id: 1, type: "Work" , name: "Writing code" },
                 { id: 2, type: "Work" , name: "Testing code" },
                 { id: 3, type: "Work" , name: "Fixing bugs" },
                 { id: 4, type: "Play" , name: "Dancing" }
             ];
         }]);
    </script>
</body>
</html>

参考

Using ngOptions in AngularJS:http://odetocode.com/blogs/scott/archive/2013/06/19/using-ngoptions-in-angularjs.aspx

本文转自博客园xingoo的博客，原文链接：AngularJS 使用ngOption实现下拉列表，如需转载请自行联系原博主。

码农公寓

下拉列表的简单使用

复杂对象，自定义列表名称

实现下拉列表的分组

按照id进行标识

参考

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